Diesel and gasoline exhaust, produced when an engine burns fuel, is a complex mixture of gases and fine particles. Recent studies have linked respiratory diseases and cancer to exposure to gasoline and diesel exhaust. These diseases, however, are also attributed to genetic susceptibility. Establishing a direct linkage of these diseases to diesel and/or gasoline exhaust requires reliable and reproducible quantitative measure of exposure. The overall aim of the proposed collaborative research is to create, evaluate and validate an autonomous/self-contained wearable, approximately 4" by 4", sensor array for the real-time monitoring of exposure through inhalation to the gaseous components of internal combustion engine exhaust. The fully integrated light weight sensor that can be worn as badge similar to y-radiation counter will comprise an array of conductometric and amperometric sensors, and low-power fully integrated microelectronics for power management, data collection, and signal processing and wireless communications. Arrays of independent sensors can offer much more analytical information on personal exposure and thus hold a great potential for selective and accurate monitoring of low concentrations of mobile source air toxics and other relevant pollutants in real-time. The conductometric and amperometric platforms have strengths that are complementary to each other and are extremely 1C compatible. Advanced data processing will be used for generating distinct response patterns and detecting the individual compounds in gaseous mixtures. Such judicious integration of two powerful detection schemes along with an intelligent data processing should dramatically increase the gathered information on personal exposure to offer remarkable reliability along with broad scope, while meeting the portability requirements of decentralized detection systems. Our multidisciplinary expertise, extensive preliminary data and successful past collaboration lay the groundwork for the proposed activity. The overall goal will be realized by 1) developing, optimizing, characterizing and testing conductometric nanosensor array, 2) developing, optimizing, characterizing and testing microfabricated amperometric sensor array 3) developing integrated microelectronics for optimal power management, data collection and signal processing and remote communication, 4) integrating conductometric and amperometric sensor arrays in a single platform with incorporated microelectronics and 5) testing and validating the wearable sensor array by monitoring in real-time diesel and gasoline exhausts under realistic exposure conditions.